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    <script>
        // 题目1(选做)：const arr=['name','age','hhh','hhh','age','hhh','hhh','hhh']各出现多少次
        // 要求输出一个对象如下：{age: 2,hhh: 5,name: 1}
        // const arr = ["name", "age", "hhh", "hhh", "age", "hhh", "hhh", "hhh"];

        // 题目2(必做)：现在两个数组，判断在a中的元素，不在b中 const a = [1,2,3,5] const b=[1,3,5,6] 将在a不在b中的筛选出来
        // 要求：输出一个数组：[2]
        const a = [1, 2, 3, 5];
        const b = [1, 3, 5, 6];
        let c = [];
        a.forEach((item) => {
            if (a.includes(item) && !b.includes(item)) {
                c.push(item);
            }
        });
        console.log(c);
        // 题目3(必做):数组去重(可以用多种方法,至少写一种)
        // 要求：输出一个数组：[1,2,3,9]
        // const arr2 = [1, 2, 3, 2, 9];

        // function fn(arr) {
        //     let newArr = [];
        //     for (let i = 0; i < arr.length; i++) {
        //         newArr.includes(arr[i]) ? newArr : newArr.push(arr[i]);
        //     }
        //     return newArr;
        // }
        // console.log(fn(arr2));
    </script>
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